linux/arch
Zhenzhong Duan 0d805ee70a xen/mmu: Call xen_cleanhighmap() with 4MB aligned for page tables mapping
When bootup a PVM guest with large memory(Ex.240GB), XEN provided initial
mapping overlaps with kernel module virtual space. When mapping in this space
is cleared by xen_cleanhighmap(), in certain case there could be an 2MB mapping
left. This is due to XEN initialize 4MB aligned mapping but xen_cleanhighmap()
finish at 2MB boundary.

When module loading is just on top of the 2MB space, got below warning:

WARNING: at mm/vmalloc.c:106 vmap_pte_range+0x14e/0x190()
Call Trace:
 [<ffffffff81117083>] warn_alloc_failed+0xf3/0x160
 [<ffffffff81146022>] __vmalloc_area_node+0x182/0x1c0
 [<ffffffff810ac91e>] ? module_alloc_update_bounds+0x1e/0x80
 [<ffffffff81145df7>] __vmalloc_node_range+0xa7/0x110
 [<ffffffff810ac91e>] ? module_alloc_update_bounds+0x1e/0x80
 [<ffffffff8103ca54>] module_alloc+0x64/0x70
 [<ffffffff810ac91e>] ? module_alloc_update_bounds+0x1e/0x80
 [<ffffffff810ac91e>] module_alloc_update_bounds+0x1e/0x80
 [<ffffffff810ac9a7>] move_module+0x27/0x150
 [<ffffffff810aefa0>] layout_and_allocate+0x120/0x1b0
 [<ffffffff810af0a8>] load_module+0x78/0x640
 [<ffffffff811ff90b>] ? security_file_permission+0x8b/0x90
 [<ffffffff810af6d2>] sys_init_module+0x62/0x1e0
 [<ffffffff815154c2>] system_call_fastpath+0x16/0x1b

Then the mapping of 2MB is cleared, finally oops when the page in that space is
accessed.

BUG: unable to handle kernel paging request at ffff880022600000
IP: [<ffffffff81260877>] clear_page_c_e+0x7/0x10
PGD 1788067 PUD 178c067 PMD 22434067 PTE 0
Oops: 0002 [#1] SMP
Call Trace:
 [<ffffffff81116ef7>] ? prep_new_page+0x127/0x1c0
 [<ffffffff81117d42>] get_page_from_freelist+0x1e2/0x550
 [<ffffffff81133010>] ? ii_iovec_copy_to_user+0x90/0x140
 [<ffffffff81119c9d>] __alloc_pages_nodemask+0x12d/0x230
 [<ffffffff81155516>] alloc_pages_vma+0xc6/0x1a0
 [<ffffffff81006ffd>] ? pte_mfn_to_pfn+0x7d/0x100
 [<ffffffff81134cfb>] do_anonymous_page+0x16b/0x350
 [<ffffffff81139c34>] handle_pte_fault+0x1e4/0x200
 [<ffffffff8100712e>] ? xen_pmd_val+0xe/0x10
 [<ffffffff810052c9>] ? __raw_callee_save_xen_pmd_val+0x11/0x1e
 [<ffffffff81139dab>] handle_mm_fault+0x15b/0x270
 [<ffffffff81510c10>] do_page_fault+0x140/0x470
 [<ffffffff8150d7d5>] page_fault+0x25/0x30

Call xen_cleanhighmap() with 4MB aligned for page tables mapping to fix it.
The unnecessory call of xen_cleanhighmap() in DEBUG mode is also removed.

-v2: add comment about XEN alignment from Juergen.

References: https://lists.xen.org/archives/html/xen-devel/2012-07/msg01562.html
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>

[boris: added 'xen/mmu' tag to commit subject]
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-09-28 08:26:30 -04:00
..
alpha Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2017-09-11 18:34:47 -07:00
arc mm: treewide: remove GFP_TEMPORARY allocation flag 2017-09-13 18:53:16 -07:00
arm The diff is dominated by the Allwinner A10/A20 SoCs getting converted to 2017-09-13 11:04:14 -07:00
arm64 arm64: stacktrace: avoid listing stacktrace functions in stacktrace 2017-09-13 18:53:16 -07:00
blackfin Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2017-09-11 18:34:47 -07:00
c6x c6x: Convert to using %pOF instead of full_name 2017-08-24 09:35:40 -04:00
cris MTD changes for 4.14: 2017-09-09 14:48:21 -07:00
frv Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2017-09-11 18:34:47 -07:00
h8300 arch: define CPU_BIG_ENDIAN for all fixed big endian archs 2017-09-08 18:26:48 -07:00
hexagon Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-09-04 11:52:29 -07:00
ia64 Merge branch 'work.ipc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-09-14 17:37:26 -07:00
m32r m32r: defconfig: cleanup from old Kconfig options 2017-09-08 18:26:51 -07:00
m68k Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu 2017-09-10 21:07:39 -07:00
metag dma-mapping updates for 4.14: 2017-09-12 13:30:06 -07:00
microblaze Merge branch 'akpm' (patches from Andrew) 2017-09-09 10:30:07 -07:00
mips Merge branch '4.14-features' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2017-09-15 20:43:33 -07:00
mn10300 mn10300: defconfig: cleanup from old Kconfig options 2017-09-08 18:26:51 -07:00
nios2 nios2 update for v4.14-rc1 2017-09-15 12:47:21 -07:00
openrisc OpenRISC patches for 4.14 2017-09-13 11:52:18 -07:00
parisc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2017-09-11 18:34:47 -07:00
powerpc * PPC bugfixes 2017-09-15 15:43:55 -07:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2017-09-12 06:01:59 -07:00
score
sh dma-mapping updates for 4.14: 2017-09-12 13:30:06 -07:00
sparc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2017-09-11 18:34:47 -07:00
tile dma-mapping updates for 4.14: 2017-09-12 13:30:06 -07:00
um Merge branch 'for-linus-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2017-09-16 12:03:25 -07:00
unicore32
x86 xen/mmu: Call xen_cleanhighmap() with 4MB aligned for page tables mapping 2017-09-28 08:26:30 -04:00
xtensa Merge branch 'akpm' (patches from Andrew) 2017-09-06 20:49:49 -07:00
.gitignore
Kconfig - For the randstruct plugin, enable automatic randomization of structures 2017-09-07 20:30:19 -07:00